Elliptic Curve Cryptography (ECC) Cipher Suites for Transport Layer Security (TLS)

Negotiated Finite Field Diffie-Hellman Ephemeral Parameters for Transport Layer Security (TLS)

“…TLS also supports Elliptic Curve Diffie-Hellman Ephemeral (ECDHE) key exchanges [RFC4492], but this document does not document their use. A registry previously used only by ECDHE-capable implementations is expanded in this document to cover FFDHE groups as well.…”

“…We use previously unallocated codepoints within the extension currently known as "elliptic_curves" (Section 5.1.1. of [RFC4492]) to indicate known finite field groups. The extension's semantics are expanded from "Supported Elliptic Curves" to "Supported Groups".…”

“…The compatible client that wants to be able to negotiate strong FFDHE sends a Supported Groups extension (identified by type elliptic_curves(10) in [RFC4492]) in the ClientHello and includes a list of known FFDHE groups in the extension data, ordered from most preferred to least preferred. If the client also supports and wants to offer ECDHE key exchange, it MUST use a single Supported Groups extension to include all supported groups (both ECDHE and FFDHE groups).…”

“…It does not cover the non-ephemeral DH key exchange mechanisms, nor does it address ECDHE key exchange, which is defined in [RFC4492].…”

“…This document updates TLS versions 1.0 [RFC2246], 1.1 [RFC4346], and 1.2 [RFC5246], as well as the TLS ECC extensions [RFC4492].…”